


Kinship through Hardship

by BumbleBooty



Series: Universal Lessons [3]
Category: Transformers - All Media Types
Genre: Implied/Referenced Torture, My poor babies, Sibling Incest, Sticky Sexual Interfacing, a prickly prick, and i had IDEAS, but I needed smut, but hes a cactus, but its alright because sides can frag the aggression out of him, fuck shockwave, hes my child too, like a certain copbot, sunshine is mildly cray cray
Language: English
Status: Completed
Published: 2017-07-08
Updated: 2017-07-08
Packaged: 2018-11-29 07:38:18
Rating: Not Rated
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,514
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11436219
Author URL: https://archiveofourown.org/users/BumbleBooty/pseuds/BumbleBooty
Summary: Sunstreaker returns from a session with Shockwave, and Sideswipe is there to comfort his twin.In the most effective way he knows how.





	Kinship through Hardship

**Author's Note:**

> Side smut for Universal Lessons. This obviously takes place before the events of the fic, but I'm putting it in as third in the series because I don't want to spoil something by actually putting it first. 
> 
> This is mildly dark, and inspired by several different 'shockwave experimented on the twins when they were Little' fics.
> 
> One in particular I recommend is Balloon Arcade's 'Hypothesis'. it's an amazing work that I can definitely credit some inspiration from.  
> (Link here: http://archiveofourown.org/works/9228269/chapters/20928908 )
> 
> to be completely honest, i've bummed myself out writing the recent chapters for the main fic, and I just needed some twins smut in my life.  
> Happy, clingy twin smut. 
> 
> s good shit. <3

Sideswipe was perfectly still on the berth, lounging on his side as one servo dangled off the edge. His eyes were blank, and he made no attempts to do...well, anything.

To put it simply, he was _exhausted_.

Shockwave had run him ragged all day, and barely gave him half a second in his brother's arms before gesturing for the other youngling to follow. It was rare that he did back-to-back experiments, but it seemed he wanted to make them suffer today. So, sides had laid down, and hadn't moved since his twin had left the room.

He was so tired he couldn't even think. He just focused himself on the uneven tenor of his brother trying to be brave while their 'lovely doctor' did whatever he pleased. Sideswipe didn't know how long he'd been like this. Pits, be didn't even know what vorn it was, let alone the orbital cycle. The only thing he did know as an absolute fact, was he and his twin were fifty-eight thousand, seven hundred and eighty-two vorns old, because shockwave was an _IMMACULATE_ note taker, and usually recorded the session. Sometimes, if Sideswipe really aggravated the scientist, he would be forced to watch the footage on repeat until he could 'identify what he did wrong.'

After a debatable eternity, the door chimed and unlocked. Sideswipe scrambled upright, sitting in the 'acceptable' waiting position just as the door slid open. Shockwave stood there, looking over the red twin for a long moment. He studied his posture, and eventually, the monotone 'acceptable' rang out. He stood to the side so an exhausted looking Sunstreaker could step into the room, doing his best to hold what was left of his dignity before the older mech.

As soon as the door chimed as locked, both mechs fell back onto the berth. Sunstreaker immediately pulled Sideswipe flush, tangling their legs together as the older twin pressed a soft kiss against the younger's forehelm. Sideswipe giggled quietly, stroking Sunstreaker's helm just behind the right fin as he pressed his face into the crook of his neck. "Missed you Sun." He purred, hitching his leg up higher around a golden hip, and let his right arm slip around his waist to lovingly rub his lower back. Sunstreaker gave a soft grunt in response, shuddering softly as Sideswipe inhaled deeply. 

"I'm glad you were still here. I needed to feel you." He muttered, squeezing the red frame even closer. Sideswipe softly stroked his twin's helm, doing his best to hide the slightly larger frame from the view of the door. Sunstreaker purred softly, taking shuddering breaths as he let his brother's field around his own calm him before a question broke the silence. "Did ya snap today?" Sunstreaker shook his helm, unable to contain the pride that came from the approving chirr that sides let out. "Good. Proud of ya." Sunstreaker tilted his helm down slightly, capturing Side's lip plates with his own. Sideswipe held Sunstreaker close, tilting his helm to allow the other to deepen the kiss at his own will. 

This opening was greatly appreciated, and Sunstreaker eagerly readjusted to deepen the kiss. He leaned up, propping himself on an elbow as he guided Sideswipe onto his back, carefully holding a crimson cheek as their kiss was mildly disturbed by his twin's laugh. "Really proud of you Sun. You're better than him and you know it!" Sides purred out, slipping his arms around his twin's neck as the other shifted to straddle his hips. "Absolutely I am. And it's all cause of you." Sunstreaker purred in return, grinning and claiming the smaller's lips one more. Sideswipe moaned quietly, moving his right arm up from Sunstreaker's hip to clutch his back as Sunstreaker shifted one hand to support the base of his helm. Both were finding it increasingly difficult to continue the kiss due to the grins on their faces, and Sideswipe was the one to break it. He dropped his lips towards Sunny's neck cabling, still grinning as he mouthed at his throat with nips and licks spread throughout the affair. Sunstreaker shuddered lightly, tilting to give Sideswipe more access. Sideswipe gave a soft moan as he gripped Sunstreaker's shoulders, letting his lips drift across the cables and down further, nipping at the sharp collar plating as he carefully sat up. Sunstreaker adjusted to sit back onto Sideswipe's lap, letting the younger twin's servos drift down to grip his thighs as he reclaimed his lips. Sunstreaker returned the kiss hungrily, letting his fingers drift across Sideswipe's chest plate.

They let their kisses deepen even further, easily succumbing to the need that was lighting their frames. Sunstreaker growled lowly, before using his weight to pin Sideswipe against the berth. He scraped his dentae down the red chest plate, feeling the seam stutter in unspoken excitement. The red mech eagerly parted his thighs, sighing happily as his twin settled between them. "You're pretty calm today. Did he run you?" Sunstreaker's question was quiet, mouthed into the thin polish on his stomach plating. Sideswipe nodded as he rested his elbows on the berth, trailing his servos over his brother's. "Yeah. He made me go over the obstacle course till I took 30 nanoclicks off my best time. Took me like, thirty tries." He let out a playful groan as Sunstreaker sat up. "Thirty? Primus, is he trying to kill you?" He ran his hands down red sides, the look of worry growing. "I'm fine Sun. Just a little tired is all." Sideswipe pulled Sunstreaker down for a soft kiss, but Sunny didn't let it linger. "You okay to go further? We can just do sparks if you want." He nuzzled his brother's faceplate with his nasal ridge, letting the feel and smell of him fill his senses.

"I'm good Sun. Just might be one good round instead of a few." Sunstreaker nodded as his hands rubbed at the inside of shapely thighs, admiring the strength of the cables beneath. "Works for me. Now, lie still and let me love you." The older twin purred out, sliding down his frame to give a long lick to the other's interface panel. Sideswipe could never deny the jolt he gave, his legs twitching tighter around Sunstreaker's chassis. He smirked silently at the ceiling as he did his best to keep his panel shut. Sunstreaker chuckled as he nuzzled a thigh-seam. "Oh, gonna play coy?" He grinned up at his brother, who was pointedly not looking at him, and really dug in. He delivered a whole slew of licks and kisses to the metal, using every trick he had ever learned to coax it into submission. Any other mech would be embarrassed at how quickly their panel popped, but Sideswipe considered it a good attempt as his spike pressurized- right into Sunstreaker's waiting mouth. He let his back arc as he gripped at the berth topper gently, always careful not to rip it. Sunstreaker eagerly suckled the stiffening rod, letting his head bob as it started to get towards the too-much-for-the-mouth stage. He kept sucking till Sides let out a pitched whine, and slowly let the spike slip from his lips. He smirked up at his twin as he stroked the eager spike in his grasp. "Someone's excited today. And here I thought you were _tired."_

Sideswipe lifted his helm to give Sunstreaker an exasperated look. "How can I be tired when you're  _sucking me off_. Primus, I'm tired, not brain-dead." He lightly kicked at the mech between his legs, but the offending limb was caught and kissed at the knee. Both twins smiled softly at each other before Sunstreaker's attention was diverted with a click. Sideswipe softly stroked his helm, leaning up onto his elbows as the golden twin's helm bowed, his glossa eagerly licking between the folds of his valve. Sides felt his optics shudder to a close, his servo resting just above his left finnial as a wet glossa slipped inside of him. Sideswipe did his best to keep his venting steady, but eventually, he fell back onto his backplate to moan quietly to the ceiling above. "Primus- _slag_ , you're too good at this!" He groaned out, letting his brother hoist his legs onto his shoulders to get a better angle. Sideswipe let his servo fall back to the berth as Sunstreaker eagerly drove his charge up. It didn't take long at all for Sunstreaker to slip a finger into his brother, kissing his anterior node as he slid his lip plates back onto the rigid spike bobbing above his head. 

Sideswipe squeaked quietly as he felt he digit invade him, shuddering hard as the wet heat enveloped his spike once more. He was slowly beginning to squirm more, his ventilations picking up with his moans. He barely managed to keep his claws in as the digit began to thrust. He could feel the heat in his faceplates growing and could feel his brother's  _pride-enjoyment-need_ pulsing through his field. He had to bite back a needy whimper when one digit became two. He bit his tongue as he gently rocked into the digits within him, his engine an idling a happy  _prrrrrr_ as Sunstreaker's head bobbed between his thighs. He risked a glance down, and felt himself clench at the sight. Sunstreaker instinctively looked up, licking a long stripe up the red and black spike as he grinned back at his brother with a lusty expression. Sideswipe fell down once more as a third digit entered him to help spread him. 

Sunstreaker watched eagerly as his twin slowly came undone beneath him, and relished the sight. They had never had any partners other than each other, and had rarely interacted with any other living mech. Naturally, Sunstreaker was very pleased whenever he could bring his brother any inkling of pleasure in this life they had been sold to. He bobbed his head like a mech on a mission, using the anarchy taking over his brother's frame to quell his own processor. He was stressed and angry, as was the point of Shockwave's experiments, but Sideswipe had never failed to walk him back from the brink of that murderous rage that often clouded his senses. His beloved Sideswipe was his mind's savior, and he thoroughly enjoyed any chance he had to give Sideswipe the same reprieve. 

When they were little, it was letting his processor wander as Sunstreaker watched over his imaginative twin. Anything they could get ahold of was used in some elaborate scheme or plot, and the stories he could spin from any object placed within his grasp served as more than enough to get Sunstreaker calmed from whatever point of anxiety he was at. As they grew, it became more of an obsession. Sunstreaker would watch the way his twin's frame moved, absolutely enthralled by even the simplest movement. On the rare days Sideswipe didn't have a story, he could often sit in his brother's lap and be allowed to explore, and Sideswipe would ramble about anything and everything he could that wasn't  _Shockwave and the awful images_. 

Then they had their first heat cycle. It was a sudden thing for both of them, and it had only been kilks between a calm silence- Sideswipe lounging in a golden embrace, his servo's joints being studied from every angle- and the sudden  _need_ that claimed both of them in a single instance. Sunstreaker could still remember how Sideswipe had stared at him when the code activated- He was entranced, like he had never seen his own twin before, and it had only taken one hesitant kiss before he found himself on the floor with a ravenous Sunstreaker atop him. After that, the two found that a physical release was an absolutely  _delightful_ way to quickly back Sunstreaker from that ominous vat of black within his processor, and helped Sideswipe maintain that boundless energy that was ever crackling through his system. 

Besides, fragging like petrorabbits was a great time-passer, and that attraction never faded. Especially when they had added merging into the mix.

Even now, Sunstreaker had to manually reject the override requests to his chest plates. His servos were quickly thrusting in and out and  _in_ , and Sideswipe squealed happily from his place on the berth. That spark of attraction was now a raging inferno, and Sunstreaker sat up to pull his digits out of his brother's valve. They glistened in the stark light of their isolation cell, and Sunstreaker's Spike bumped against his panel once more. This time, however, he allowed it to spring free completely, biting his lip as he used Sideswipe's own lubricant to slick up his spike. Sideswipe let out a hungry moan, sliding his arms around Sunstreaker's neck as the other shifted to loom over him. His clean servo gripped his brother's hip as he angled him upwards, and his stained one guided his spike into the clenching heat. 

Both twins moaned as Sunstreaker entered Sideswipe, letting his helm drop to rest on his shoulder as he pushed in slowly. He would argue that this was the best part, where Sideswipe's impatient nature wanted him in  _faster faster faster!_ Soon enough though, Sunstreaker found himself fully seated within Sideswipe, kissing him throughly as he waited for him to adjust. He didn't have to wait long. 

It was maybe a kilk at most before Side's hips ground against his own, a hungry moan easily slipping free as Sunstreaker carefully gave a gentle test-thrust. Seemingly satisfied, Sunstreaker angled his Brother's hips a little higher before starting in earnest, enjoying the feeling of Sideswipe's servos clawing at his shoulders. He really must have been tired if his claws were already out. Primus, his paint would be  _ruined_ by the end of this! Luckily, he had behaved well enough to get a new can of primer about ten sessions ago. He growled as he ground hard against his twin, his plating ruffling as he bit at his twin's neck. He always felt so fragging  _good_ , tangled up in matching arms as he worked off his aggression. And Sides was always so  _vocal_ , always begging for more, or harder, or _Primus, please, **faster**_ , and Sunstreaker was always eager to please. Their hips surged against each other, their paint transferring from the force of the thrusts jarring them together. Sideswipe had dissolved into chirps and clicks, a telling sign he was so very, very close to the edge already. Sunstreaker shifted again, bracing himself on his forearms more evenly and pressing their helms together. 

"Your spark Sides...let me have it back." He purred lowly, watching Sideswipe shudder. Half a nanosecond later, his chest split open, revealing an irising spark chamber and the pulsing pink of his Amaranth spark- the match to his own. Sunstreaker growled possessively as he let his own plates split, shielding his twin's essance with his.

For a brief moment, they were one once more. A single mech lost to his ecstasy, whole and fulfilled. Soon enough, the overload subsided, and all that was left was contentment and the blissful drop of recharge. 

 


End file.
